CHARLESTON, S.C. (AP) — Joe Biden has claimed one of South Carolina's most coveted endorsements, from Congressman Jim Clyburn,  the highest-ranking black member of Congress and a South Carolina political kingmaker.

Clyburn made his announcement Wednesday, a day after Democratic presidential candidates debated in the state.

Front-runner Bernie Sanders spoke at an Al Sharpton breakfast.

And Pete Buttigieg, a leading critic of both Biden and Sanders, canceled multiple events saying he was sick.

The developments came just three days before South Carolina's presidential primary election — and six days before Super Tuesday — with the Democratic establishment growing increasingly concerned that Sanders, a polarizing progressive, is tightening his grip on his party's nomination.

Enter your number to get our free mobile app